Overhaul Is Ventilation: Providing Air to Concealed Spaces

Appearances Can Be Deceiving 

By Nicholas Papa

Never let your guard down, always do your due diligence, and trust your gut. These are the lessons that were strongly reinforced at a structure fire I operated at on the afternoon of Monday, January 3, 2016. We were the third-due engine company responding to a confirmed fire in a small, one- and a-half story bungalow (dormered second-floor living area). The first-arriving company found the rear porch involved in fire and stretched a 1¾-inch handline. On our arrival, we were assigned primary search, along with the ladder company, who was just pulling up. As we walked up to the house, no smoke could be seen, and it appeared that the incident was essentially under control.

(1)  A-side view of the 1½-story, wood-frame (bungalow-style), single-family dwelling (Photos by Deputy Chief Scott Morgan.)                                           

                                                                                                                                      (2)  Covered, rear porch, on the C-side of the  structure, which was involved in fire on arrival.

We assisted with forcing entry to the front door and conducted a search of the first floor under pristine conditions. The search proved negative. We proceeded to the second floor to link up with the ladder company and check for extension. We encountered a mild smoke condition, but the characteristics were stagnant and thin –remaining just above head height. On scanning the room with the thermal imaging camera, only a slight heat signature (125°-135°F) was detected on a small portion of the C-side wall (toward the BC corner) in the back bedroom. The wall was not hot to the touch, and no discoloration of the paint was visible. At a cursory glance, it all appeared to be just residual heat and smoke from the exterior fire directly below.


Training Minutes: Coordinated Ventilation

Training Minutes: Taking Windows and Horizontal Ventilation

Training Minutes: OV Firefighter and Size-Up

First-Due Battalion Chief: Overhaul

The firefighter working in the irons position of the ladder company happened to catch a wisp of smoke pushing from the window frame. Sensing that something did not feel right, he brought it to the attention of his officer and a small (softball-sized) inspection hole was opened in the wall. Flame and smoke instantly presented within the hole, prompting an immediate request for a line to our location.  Inside of a minute’s time, that small flame started blow-torching out, extending up the side of the wall, and began spreading across the ceiling, filling the room with smoke, banking right down on top of us. To slow the fire’s progress, we quickly shut the windows (which had been opened earlier to evacuate the smoke) and attempted to control the bedroom door, only to discover there was no door.

(3) The underside of the porch roof where the fire had extended and gained access to the exterior wall stud channel, allowing it to communicate to the second floor. (Photo by Inspector Eddie Irizarry). (4) The exterior view of the second floor, back bedroom, located directly above the fire area. The circled area identifies the wall through which the fire extended. (Photo by Deputy Chief Scott Morgan).                                                                                                                                                                                                                                                                                                     

With conditions rapidly deteriorating, the adjacent closet door was hastily removed as we exited the bedroom. The door was then placed in the frame to seal off the room. Being heads-up, a member of my crew proceeded down the stairs to intercept the line being stretched, cutting down on the lag time and reducing the number of bodies in the already congested second-floor hallway. As we waited, we could see through the gaps of the door and watched as the fire continued to roll across the ceiling and the neutral plane drop about halfway to the floor. The line seemed to appear just in time and was advanced into the room, extinguishing the fire even more quickly than it had spread. The fire was contained to that room; thankfully, no one was injured.  The outcome of this incident could have been dramatically different, had it not been for the members reacting so swiftly and decisively.



(5)  The interior view of the second-floor rear bedroom that shows the knee wall from where the fire spread. (Photos by Inspector Eddie Irizarry). (6) The diagonal line of demarcation along the top left corner of the window frame can be traced down to the exact point in the wall where the inspection hole was created.

The fire in the back porch below had communicated to the common stud channel running up to the room we were in on the second floor. The hidden pocket of fire quickly consumed the oxygen within the concealed space and became ventilation-controlled and erupted when given the proper concentration of oxygen, which was introduced by the inspection hole created during overhaul and was exacerbated by the open windows and absent bedroom door.  The fire behavior encountered during this incident displays the volatility of vent-controlled fires and the diligence that must be exercised when opening up any concealed space [where fire may be present]. This highlights the importance of positional discipline and coordinating fireground operations.

Taking Precautions

When investigating for fire extension, you may use greater scrutiny, especially when operating on the floor above the fire. Enlist all of your senses; do not rely solely on the [temperature] readings of your thermal imaging camera. Watch for smoke issuing from cracks and seams (under pressure) and blistering or discolored paint or wallpaper. Listen for low rumbling sounds coming from behind walls or ceilings. Feel the wall or ceiling in question (with the back of a bare hand) for heat and see if you can comfortably hold it there.  Do not forget about the all-important sixth sense, intuition–the “gut feeling.” If something does not feel right, it probably is not so; never leave any stone unturned. The potential benefits of being [overly] cautious or following a hunch (as long as it is coordinated) far outweighs the consequences of an oversight.       

Any opening that leads to the area of involvement must be viewed as a source of ventilation, even openings created in the walls and ceilings. We must isolate the fire, control the existing openings, and delay creating additional ones until a charged handline is in position. Temporarily restricting the air flow will aid in confining the fire and limiting its growth (heat output) while handlines are being stretched/advanced. As such, (pre-fire control) overhaul should be treated as ventilation. If fire in the concealed spaces is suspected, ensure that a handline is in place prior to opening up. Once a ventilation-controlled fire is given a fresh supply of oxygen, it can gain momentum at an overwhelming pace. Having a handline at the ready will ensure that any fire encountered will be rapidly extinguished.  Consider using the often underused pressurized (2½-gallon) water can. In the hands of a skilled operator, the can provide enough knockdown power to keep a fire in check until the stream of a handline can be applied.                        

Maintaining situational awareness is essential to recognizing critical pieces of information as they become available and appropriately addressing the conditions at hand.  The implications of possessing a complacent mindset or even a momentary loss of focus can be severe. A single lapse in judgment or oversight can be all that it takes to alter the course of an incident. Free-flow communication is integral to the timely dissemination of critical information. As Colonel (Ret.) Peter Blaber states, “It’s not reality unless it is shared.” Obtaining continuous updates from those in key (physical) positions is paramount to successful decision making and execution. The effectiveness/efficiency of an operation is directly correlated to the level of coordination and competency of those involved. The common denominator of a successful outcome, then, is the result of strict fireground discipline and tactical proficiency.

Nicholas Papa is a lieutenant with the New Britain (CT) Fire Department, where he is assigned to Engine Co. 1. He has had 14 years of experience in career and volunteer agencies. Previously, he served with the Newington (CT) Fire Department. Papa is a member of the UL-FSRI Advisory Panel for the Study of Coordinated Fire Attack in Acquired Structures. He is a frequent contributor to Fire Engineering, the co-host for the BlogTalk Radio Show Politics & Tactics, and an FDIC International classroom instructor. 

 Originally ran October 18, 2018.

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